Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics B Atomic Molecular and Optical Physics

Resonant dynamics in a quasi-2D atomic boson–fermion mixture

Michiel Wouters, Jacques Tempere, J. T. Devreese

Published Mar 24, 2004• 1 citation
Publisher

Abstract

The time evolution of a boson–fermion mixture that is strongly confined in one direction is studied when a magnetic field is suddenly brought close to an interspecies Feshbach resonance. We predict that the atom–molecule oscillations that occur in the three-dimensional case will also be present in the quasi-two-dimensional case and compute the change in frequency and the number of cold fermions remaining after the Feshbach regime is switched on.

DOI
10.1088/0953-4075/37/7/068

Related papers

Resonant dynamics in boson-fermion mixtures

Michiel Wouters, Jacques Tempere, J. T. Devreese

The time evolution of a dilute atomic boson-fermion mixture is studied at zero temperature, when the external magnetic field is brought close to an interspecies Feshbach resonance. On short time scales we find that before a collapse or phase separation of the mixture can occur, oscillations between fermionic atoms and heteronuclear molecules dominate the dynamics. Applying the model presented here to a trapped mixture of ${}^{40}\mathrm{K}{\ensuremath{-}}^{87}\mathrm{Rb}$ atoms, we find that the predicted oscillations can be revealed in degenerate mixtures of these atoms.

arXiv:cond-mat/0303220•Physical Review A•Jun 25, 2003•15 citations

Coherent atom-molecule oscillations in a Bose-Fermi mixture

M. L. Olsen, John D. Perreault, Tyler D. Cumby +1 more

We create atom-molecule superpositions in a Bose-Fermi mixture of $^{87}\text{R}\text{b}$ and $^{40}\text{K}$ atoms. The superpositions are generated by ramping an applied magnetic field near an interspecies Fano-Feshbach resonance to coherently couple atom and molecule states. Rabi- and Ramsey-type experiments show oscillations in the molecule population that persist as long as $150\text{ }\ensuremath{\mu}\text{s}$ and have up to 50% contrast. The frequencies of these oscillations are magnetic-field dependent and consistent with the predicted molecule binding energy. This quantum superposition involves a molecule and a pair of free particles with different statistics (i.e., bosons and fermions) and furthers exploration of atom-molecule coherence in systems without a Bose-Einstein condensate.

arXiv:0810.1965•Physical Review A•Sep 2, 2009•22 citations

Feshbach resonances in a quasi-two-dimensional atomic gas

Michiel Wouters, Jacques Tempere, J. T. Devreese

Strongly confining an ultracold atomic gas in one direction to create a quasi-two-dimensional system alters the scattering properties of this gas. We investigate the effects of confinement on Feshbach scattering resonances and show that strong confinement results in a shift in the position of the Feshbach resonance as a function of the magnetic field. This shift, as well as the change of the width of the resonance, is computed. We find that the resonance is strongly damped in the thermal gas, but in the condensate the resonance remains sharp due to many-body effects. We introduce a two-dimensional model system, suited for the study of resonant superfluidity and having the same scattering properties as the tightly confined real system near a Feshbach resonance. Exact relations are derived between measurable quantities and the model parameters.

arXiv:cond-mat/0305235•Physical Review A•Nov 3, 2003•21 citations

Dynamics of small trapped one-dimensional Fermi gas under oscillating magnetic fields

Xiangyu Yin, Yangqian Yan, Dane Hudson Smith

Deterministic preparation of an ultracold harmonically trapped one-dimensional Fermi gas consisting of a few fermions has been realized by the Heidelberg group. Using Floquet formalism, we study the time dynamics of two- and three-fermion systems in a harmonic trap under an oscillating magnetic field. The oscillating magnetic field produces a time-dependent interaction strength through a Feshbach resonance. We explore the dependence of these dynamics on the frequency of the oscillating magnetic field for noninteracting, weakly interacting, and strongly interacting systems. We identify the regimes where the system can be described by an effective two-state model and an effective three-state model. We find an unbounded coupling to all excited states at the infinitely strong interaction limit and several simple relations that characterize the dynamics. Based on our findings, we propose a technique for driving transition from the ground state to the excited states using an oscillating magnetic field.

arXiv:1608.06966•Physical Review A•Oct 21, 2016•5 citations

Mixing-demixing transition and collapse of a vortex state in a quasi-two-dimensional boson-fermion mixture

Sadhan K. Adhikari, Luca Salasnich

We investigate the mixing-demixing transition and the collapse in a quasi-two-dimensional degenerate boson-fermion mixture (DBFM) with a bosonic vortex. We solve numerically a quantum-hydrodynamic model based on a new density functional which accurately takes into account the dimensional crossover. It is demonstrated that with the increase of interspecies repulsion, a mixed state of DBFM could turn into a demixed state. The system collapses for interspecies attraction above a critical value which depends on the vortex quantum number. For interspecies attraction just below this critical limit there is almost complete mixing of boson and fermion components. Such mixed and demixed states of a DBFM could be experimentally realized by varying an external magnetic field near a boson-fermion Feshbach resonance, which will result in a continuous variation of interspecies interaction.

arXiv:0704.2373•Physical Review A•May 8, 2007•19 citations

Fermionic quantum mixtures with tunable interactions

Rudolf Grimm, Cosetta Baroni

The topic of the present lecture notes are two-species quantum mixtures composed of a deeply degenerate Fermi gas and a second component, the latter being fermionic or bosonic. A key ingredient is the possibility to tune the $s$-wave interaction between the different species by means of magnetically controlled Feshbach resonances, which allow us to investigate regimes of strong interactions. In two case studies, we review our experiments on mixtures of $^6$Li fermions with fermionic $^{40}$K or bosonic $^{41}$K atoms and on mixtures of fermionic $^{161}$Dy with $^{40}$K atoms. We cover various topics of fermionic quantum many-body physics, ranging from impurity physics and quasiparticles over phase separation to the formation of ultracold molecules and progress towards novel superfluids.

arXiv:2311.01220•Nov 2, 2023•0 citations
The time evolution of a boson–fermion mixture that is strongly confined in one direction is studied when a magnetic field is suddenly brought close to an interspecies Feshbach resonance. We predict that the atom–molecule oscillations that occur in the three-dimensional case will also be present in the quasi-two-dimensional case and compute the change in frequency and the number of cold fermions remaining after the Feshbach regime is switched on.
The time evolution of a dilute atomic boson-fermion mixture is studied at zero temperature, when the external magnetic field is brought close to an interspecies Feshbach resonance. On short time scales we find that before a collapse or phase separation of the mixture can occur, oscillations between fermionic atoms and heteronuclear molecules dominate the dynamics. Applying the model presented here to a trapped mixture of ${}^{40}\mathrm{K}{\ensuremath{-}}^{87}\mathrm{Rb}$ atoms, we find that the predicted oscillations can be revealed in degenerate mixtures of these atoms.
We create atom-molecule superpositions in a Bose-Fermi mixture of 87Rb^{87}\text{R}\text{b}87Rb and 40K^{40}\text{K}40K atoms. The superpositions are generated by ramping an applied magnetic field near an interspecies Fano-Feshbach resonance to coherently couple atom and molecule states. Rabi- and Ramsey-type experiments show oscillations in the molecule population that persist as long as $150\text{ }\ensuremath{\mu}\text{s}$ and have up to 50% contrast. The frequencies of these oscillations are magnetic-field dependent and consistent with the predicted molecule binding energy. This quantum superposition involves a molecule and a pair of free particles with different statistics (i.e., bosons and fermions) and furthers exploration of atom-molecule coherence in systems without a Bose-Einstein condensate.
Strongly confining an ultracold atomic gas in one direction to create a quasi-two-dimensional system alters the scattering properties of this gas. We investigate the effects of confinement on Feshbach scattering resonances and show that strong confinement results in a shift in the position of the Feshbach resonance as a function of the magnetic field. This shift, as well as the change of the width of the resonance, is computed. We find that the resonance is strongly damped in the thermal gas, but in the condensate the resonance remains sharp due to many-body effects. We introduce a two-dimensional model system, suited for the study of resonant superfluidity and having the same scattering properties as the tightly confined real system near a Feshbach resonance. Exact relations are derived between measurable quantities and the model parameters.
Deterministic preparation of an ultracold harmonically trapped one-dimensional Fermi gas consisting of a few fermions has been realized by the Heidelberg group. Using Floquet formalism, we study the time dynamics of two- and three-fermion systems in a harmonic trap under an oscillating magnetic field. The oscillating magnetic field produces a time-dependent interaction strength through a Feshbach resonance. We explore the dependence of these dynamics on the frequency of the oscillating magnetic field for noninteracting, weakly interacting, and strongly interacting systems. We identify the regimes where the system can be described by an effective two-state model and an effective three-state model. We find an unbounded coupling to all excited states at the infinitely strong interaction limit and several simple relations that characterize the dynamics. Based on our findings, we propose a technique for driving transition from the ground state to the excited states using an oscillating magnetic field.
We investigate the mixing-demixing transition and the collapse in a quasi-two-dimensional degenerate boson-fermion mixture (DBFM) with a bosonic vortex. We solve numerically a quantum-hydrodynamic model based on a new density functional which accurately takes into account the dimensional crossover. It is demonstrated that with the increase of interspecies repulsion, a mixed state of DBFM could turn into a demixed state. The system collapses for interspecies attraction above a critical value which depends on the vortex quantum number. For interspecies attraction just below this critical limit there is almost complete mixing of boson and fermion components. Such mixed and demixed states of a DBFM could be experimentally realized by varying an external magnetic field near a boson-fermion Feshbach resonance, which will result in a continuous variation of interspecies interaction.
The topic of the present lecture notes are two-species quantum mixtures composed of a deeply degenerate Fermi gas and a second component, the latter being fermionic or bosonic. A key ingredient is the possibility to tune the sss-wave interaction between the different species by means of magnetically controlled Feshbach resonances, which allow us to investigate regimes of strong interactions. In two case studies, we review our experiments on mixtures of 6^66Li fermions with fermionic 40^{40}40K or bosonic 41^{41}41K atoms and on mixtures of fermionic 161^{161}161Dy with 40^{40}40K atoms. We cover various topics of fermionic quantum many-body physics, ranging from impurity physics and quasiparticles over phase separation to the formation of ultracold molecules and progress towards novel superfluids.